A. Field of the Invention
The present invention relates to a reticle transport apparatus for transporting a reticle with respect to an exposure atmosphere chamber, an exposure apparatus comprising the reticle transport apparatus, a reticle transport method, and a reticle processing method.
B. Description of the Related Art
Recently developed projection exposure apparatuses expose the pattern of a reticle onto a photosensitive substrate using extreme ultraviolet (EUV) light in the range of wavelengths of approximately 5˜40 nm. In EUVL (extreme ultraviolet light lithography) exposure apparatuses, because EUV light is absorbed by air, a high degree of vacuum is maintained within the chamber that accommodates the apparatus, and special contrivances are also necessary when transporting the reticle.
A reflecting type reticle is typically used in the EUVL exposure apparatus, because few materials have a high transmittivity with respect to short wavelength light. A transparent thin film called a pellicle may protect the pattern surface of a reticle used in an exposure apparatus that uses normal visible light or ultraviolet rays. However, in the EUV exposure apparatus, it is not possible to form a pellicle, because there are few materials that have high transmittivity with respect to short wavelength light. Therefore, at the time of reticle transport and storage, the reticle is covered within a protective cover (protective member), and the pattern region of the reticle is protected (see U.S. Pat. No. 6,239,863).
While the reticle is protected within the protective cover and transported, the reticle and the protective cover may come into contact, and debris may be generated at that contact point. Foreign matter that has occurred due to the generation of debris may thus accumulate, and the pattern region of the reticle may be contaminated.